JPH0362986B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to refrigeration systems, and more particularly to a discharge valve and buttful assembly for controlling the flow of high pressure gaseous refrigerant from a compressor to a condenser. .

BACKGROUND OF THE INVENTION In addition to an evaporator and a condenser, many refrigeration systems include a compressor that draws low-pressure gaseous refrigerant from the evaporator, compresses it to a high pressure, and supplies the high-pressure gaseous refrigerant to the condenser. I'm here.
Several unfavorable transient conditions exist during operation of a refrigeration system. For example, in a centrifugal compressor, one such unfavorable transient condition is
It is a surge condition in which refrigerant backflows, thereby reducing efficiency in the refrigeration system and potentially harming various components of the refrigeration system.

Another transient condition in centrifugal compressors is
This occurs when the refrigeration system is started after the operation of the double compressor refrigeration system has been temporarily stopped due to a small refrigerant load. When one of the compressors is started, there may be some established pressure head that requires excessive torque to start the compressor. It is said that For example, in a centrifugal compressor, starting the compressor against a certain established pressure head will not bring the compressor to full rotational speed.

Yet another unfavorable transient condition is primarily associated with refrigeration systems having at least two compressors. This transient condition occurs when one compressor is on and the other compressor is off. An operating compressor may cause refrigerant to flow back toward or through an inactive compressor. Such conditions may also occur in refrigeration systems having only one compressor.

Current attempts to prevent the occurrence of these undesirable transient conditions include the provision of discharge check valves between the compressor and condenser, which reduce the effects of certain established pressure heads on compressor start-up. eliminate,
There is also a method to prevent refrigerant from flowing backwards through the compressor.

However, such conventional discharge check valves have several drawbacks. One of its drawbacks is that the valve repeatedly cycles between open and closed positions under surge conditions. This leads to premature valve failure and undesirable noise during compressor operation.

Another drawback of current check valves is that
The valve acts as a barrier to refrigerant flow, creating an undesirably high pressure drop between the compressor and condenser.
A large pressure drop is created by the circuitous path that refrigerant must follow to flow through the valve.

Yet another problem with conventional check valves is that they do not act as a buffer for refrigerant flowing from the compressor to the condenser. This necessitates the formation and placement of a separate baffle member within the condenser to direct the high pressure incoming flow, for example, between the heat exchange tubes within the shell and between the tube condensers. Ru.

SUMMARY OF THE INVENTION One object of the present invention is to provide an improved drain valve for a refrigeration system.

Another object of the present invention is to provide a drain valve and baffle assembly for a refrigeration system.

Yet another object of the present invention is to prevent repetitive movement of the valve element of the exhaust valve under surge or part load conditions.

Yet another object of the invention is to eliminate the effects of certain established pressure heads on compressor start-up.

Yet another object of the invention is to prevent backflow within the compressor.

Yet another object of the present invention is to substantially eliminate large pressure drops between the compressor and condenser.

Yet another object of the present invention is to provide a drain valve and buffle assembly that performs the function of a baffle in combination with a drain valve.

In one form of the invention, an inlet for receiving fluid flow, an outlet for providing fluid flow, and a valve member movable between a closed position for closing the outlet and an open position for opening the outlet. and a mechanism for releasably retaining the valve member when the valve member is in an open position.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention will be explained in detail below by way of example embodiments with reference to the accompanying figures.

EXAMPLE The attached FIG. 1 shows the corresponding motors 16 and 18.
A multi-compressor refrigeration system 10 is shown including two compressors 12 and 14 driven by compressors 12 and 14. Compressors 12 and 14 may be of the same or different capacity and each has a discharge conduit 20 connected in fluid communication with a condenser 24.
and 22. Similarly compressors 12 and 1
4 have suction conduits 26 and 28, respectively, in fluid communication with the evaporator 30. Although the invention is described herein with reference to a dual compressor refrigeration system 10, the invention may also be applied to single compressor refrigeration systems.

In FIGS. 2 and 3, the exhaust valve and baffle assembly 32 of the present invention is shown in the condenser 24 and compressor 12.
Illustrated in connection with. A similar discharge valve and buttful assembly 32 may also be provided in the compressor 14, and since the assemblies are identical in function and construction, the present invention will now be described only in the context of the compressor 12. do. Evaporator 30 is not shown in FIGS. 2 and 3, nor is an expansion device commonly incorporated into typical refrigeration systems. Condenser 24 includes a shell 34 containing a plurality of heat exchange tubes 36 supported therein and supplying the fluid to be heated. The condenser 24 also has a hole 38 into which a drain valve and baffle assembly 32 is mounted. Assembly 32 is hermetically fitted in hole 38 and secured by annular mounting support 40. The hermetic fit may be achieved by any suitable means, such as by welding.

The exhaust valve and buttful assembly 32 is connected to the exhaust conduit 20.
an inlet 42 in fluid communication with the condenser 2;
4 and an outlet 44 opening into the interior of the tube. Inlet 42 and outlet 44 constitute opposite ends of a valve conduit 46 according to the invention.

Furthermore, the assembly 32 includes a battle full and shield device 4.
8, the device includes a substantially continuous side wall 50 closed at one end by an end wall 52. Device 48 is spaced apart from and aligned with outlet 44 of valve conduit 46. The device 48 also has a second support arm 56 and a suction pipe 76.
Fixed in place as shown in the Figures and FIG. 3, the two support arms 56 and suction pipes 76 are spaced 120 degrees apart from each other. pipe 7
6 is welded to the end wall 52. Structural members 54 may be used to provide additional support to device 48.

A collar bearing 58 is secured to the end wall 52 in any suitable manner and has a bore 60 therein that opens into a vent chamber 62 . Ventilation chamber 6
2 is closed by an end plate 64.

Assembly 32 further includes a valve plate 66 mounted against outlet 44 as shown in FIG. Valve plate 66 is movable between a closed position of FIG. 2 in which it closes outlet 44 and an open position of FIG. 3 in which it opens outlet 44. A valve stem 68 is integrally connected to or formed integrally with the valve plate 66 and is slidably received within the bore 60 . Valve plate 66 has an aperture 70 for receiving support arm 56.
The shape of hole 70 is preferably complementary to and slightly larger than the shape of support arm 56 so that support arm 56 has a tight sliding fit thereto. A spring 69 is interposed between the end wall 52 and the valve plate 66 about the collar bearing 58 to bias the valve plate 66 to the closed position.

Valve stem 68 communicates with axial vent passage 72 and with condenser 2 when valve plate 66 is in its closed position as shown in FIG.
and at least one radial ventilation passage 74 communicating with the interior of 4. Axial ventilation passage 7
2 opens into the ventilation chamber 62. Suction pipe 76
is in communication with the ventilation chamber 62 and extends through a hole 78 provided in the valve plate 66. The shape of the hole 78 is complementary to and slightly larger than the shape of the suction pipe 76 so that the suction pipe 76 has a tight sliding fit therein. The suction pipe 76 extends through the hole 80 in a gas-tight manner and is connected to the compressor 12. The other end of suction pipe 76 must be connected to a low pressure area, such as behind the evaporator 30, suction conduit 26, or guide vanes (not shown) of compressor 12. As shown in Figures 2 and 3,
The suction pipe 76 is connected to the suction side of the compressor 12, and a solenoid valve 82 for selectively controlling communication of the suction pipe 76 is provided in the middle thereof. The solenoid valve 82 is electrically connected to the motor 16, so that when the motor 16 is energized, the solenoid valve 82 is also energized, thereby establishing communication with the suction pipe 76. When the power supply to the motor 16 is stopped, the power supply to the solenoid valve 82 is also stopped, thereby cutting off communication with the suction pipe 76. Thus, when the motor is started, the solenoid valve 82 is opened, and when the motor is stopped, the solenoid valve 82 is closed. Alternatively, solenoid valve 82 may be independently operated by a microcomputer (not shown) for the refrigeration system.

For the purpose of explaining the operation of the present invention, compressor 14 is in operation, sucking gaseous refrigerant from evaporator 30 and compressing it, supplying high pressure gaseous refrigerant to condenser 24. Assume that Assume further that compressor 12 is stopped and its valve plate 66 is in the closed position shown in FIG. In this case, the valve plate 66 is connected to the spring 6
9 urges the valve to the closed position. Furthermore, since the motor 16 is not operating, the solenoid valve 82 is demagnetized and communication with the suction pipe 76 is cut off. In such a situation, the axial ventilation passage 72 and the radial ventilation passage 74 will allow the condenser 2 to
The pressures between the inside of 4 and the ventilation chamber 62 are equalized. In the closed position, radial ventilation passage 74 is open and in communication with the interior of condenser 24. However, in the open position, as shown in FIG.
Communication with the condenser 24 is substantially cut off by the inner side wall surface of the condenser 24 .

Assuming now that the refrigerant load is such that compressor 12 needs to be brought on-line, there is some established pressure head due to compressor 14 operation. Valve plate 66 is maintained in the closed position by spring 69 to eliminate the effect of the pressure head established in compressor 12 during its start-up.
Additionally, the communication of vent passages 72 and 74 with condenser 24 prevents valve plate 66 from opening prematurely until compressor 12 reaches a certain speed. Thus, when current is supplied to the motor 16, the compressor 12 is quickly brought to a speed to match the pressure head present therein, and upon energizing the motor 16, the solenoid valve 82 is energized and the suction pipe 76 is energized. is communicated.

For purposes of clarity, terms used hereafter will be defined or explained. In any refrigeration system, the compressor is the suction or suction source that draws or sucks gaseous refrigerant from the evaporator. Therefore, "aspiration", "inhalation", "aspirate", "inhale"
The words do the same thing and can be used interchangeably. Furthermore, the word "vacuum" does not mean an absolute vacuum, but rather a vacuum-like state. Thus, the terms "vacuum,""vacuum-like,""nearvacuum,""partialvacuum," and "low pressure source" are used because they describe a space from which a substantial amount of fluid has been removed. When used, they mean the same thing.

In FIG. 2, compressor 12 generates a gaseous gas at a high enough pressure to overcome the force of spring 69, thereby driving valve plate 66 from the closed position to the open position shown in FIG. Valve plate 66 is maintained in the closed position by spring 69 until a velocity is established to direct the flow of refrigerant through discharge conduit 20 and inlet 42 . Once the valve plate is driven into position, the radial ventilation passage 74 is effectively cut off from communication with the condenser 24 by the inner wall of the bore 60. Since the solenoid valve 82 is energized together with the motor 16, the suction pipe 76 communicates with the ventilation chamber 62 suction source (in this case, the suction side of the compressor 12 downstream of the guide vanes, not shown). Connecting. The suction effect provided by compressor 12 substantially evacuates vent chamber 62 to remove air and other fluids, thereby creating a vacuum or near-vacuum condition. The suction action provided by compressor 12 through vent chamber 62 and vent passages 72, 74 draws valve plate 66 downwardly into an open position as shown in FIG. The suction force provided by compressor 12 is greater than the spring force provided by spring 69, thereby maintaining valve plate 66 in the open position.

Compressor 1 via suction pipe 76 and ventilation chamber 62
The suction force provided by 2 is sufficient to maintain the valve plate 66 in the open position against the spring force of the spring 69, so that the suction force provided by the valve plate 66 is sufficient to maintain the valve plate 66 in the open position against the spring force of the spring 69. does not move repeatedly between the open and closed positions. This is particularly advantageous under surge conditions where refrigerant backflow occurs.

As mentioned above, "vacuum-like" or "near vacuum"
The term is primarily used to describe the pressure within vent chamber 62 that is not an absolute vacuum but is much lower than the high pressure environment within condenser 24.

During operation of the compressor 12, the valve plate 66 of the baffle and shield device 48 diverts the incoming flow of high pressure gaseous refrigerant from directly impinging the heat exchange tube 36 and directs it into the condenser 24. to a predetermined area, thereby allowing the heat exchange tube 36 to
Acts as a buffer to provide uniform flow over the entire length of the tube. Additionally, during surge conditions where refrigerant backflow occurs, buffling and shielding device 48 shields valve plate 66 from the forces of refrigerant backflow, so that the suction force provided by compressor 12 is transferred to valve plate 66 during surge conditions. The function is to assist in maintaining the valve in the open position.

When the refrigerant load is such that it is desirable to shut down the compressor 12, the motor 16 and the solenoid valve 82 are de-energized, thereby disconnecting the suction pipe 76, thereby shutting down the compressor 12. The suction force provided by 12 is eliminated. The suction force is eliminated and the valve stem 68 and bore 60
Since a certain amount of refrigerant is allowed to leak between the vent chamber 62 and the condenser 24, the pressure in the vent chamber 62 begins to rise to the pressure in the condenser 24, causing the spring 69 to move the valve plate 66 from the open position to the closed position. It becomes possible to apply force to

If the suction pipe 76 is connected behind the inlet guide vane (not shown) of the compressor 12 and the guide vane is closed before shutting down the compressor 12;
The pressure within vent chamber 62 increases allowing spring 69 to drive valve plate 66 to the closed position. Under surge conditions, the pressure behind the inlet guide vanes also rises to a pressure close to the condenser internal pressure, but this pressure rises and falls in short periods.
By appropriately setting the size of the suction pipe 76 and the size of the clearance between the valve stem 68 and the collar bearing 58, the pressure in the vent chamber 62 can be increased quickly enough to move the valve plate 66 to the closed position. rising is prevented.

Although the exhaust valve and baffle assembly 32 has been described above with respect to a dual compressor type refrigeration system 10, the present invention may also be applied to a single compressor type refrigeration system. In single compressor refrigeration systems, holes 70 and 78 in valve plate 66 are preferably eliminated. In this case, the support arm 56 is mounted on the radially outer surface of the valve conduit 46 and side wall 50 and the suction pipe 76 extends through the shell 34 rather than through the valve plate 66 and valve conduit 46. Piped directly to the outside. Such an arrangement structure of the support arm 56 and the suction pipe 76 may be employed in the dual compressor type refrigeration system 10. However, as shown in FIGS. 2 and 3, small leaks that occur through holes 70 and 78 do not adversely affect the performance of the present invention.

Although the present invention has been described in detail with respect to specific embodiments above, the present invention is not limited to such embodiments, and various other embodiments are possible within the scope of the present invention. This will be clear to those skilled in the art.

[Brief explanation of drawings]

FIG. 1 is a front view of a dual compressor type refrigeration system incorporating a preferred embodiment of the present invention. FIG. 2 is a cross-sectional view of a preferred embodiment of the present invention incorporated into a condenser of a partially illustrated refrigeration system in a closed state. FIG. 3 is a sectional view similar to FIG. 2 showing the embodiment shown in FIG. 2 in an open position. 10... Refrigeration system, 12, 14... Compressor, 16, 18... Motor, 20, 22... Discharge conduit, 24... Condenser, 26, 28... Suction conduit, 30... Evaporator, 32... ... Discharge valve and buttful assembly, 34 ... Shell, 36 ... Heat exchange tube, 38 ... Hole, 40 ... Support, 42
...Inlet, 44...Outlet, 46...Valve conduit, 48
... Batsuful and shield device, 50 ... Side wall,
52... End wall, 54... Structural member, 56... Support arm, 58... Collar bearing, 60... Bore, 6
2... Ventilation chamber, 64... End plate, 66...
... Valve plate, 68 ... Valve shaft, 69 ... Spring, 7
0... hole, 72, 74... ventilation passage, 76... suction pipe, 78, 80... hole, 82... solenoid valve.

Claims (1)

[Scope of Claims] 1. Refrigeration including an evoparator, a compressor that sucks gaseous refrigerant from the evoparator and compresses the gaseous refrigerant to a high temperature and high pressure, and a condenser that receives the gaseous refrigerant compressed to the high pressure. a discharge valve and baffle assembly for the apparatus, comprising: an inlet connected to the compressor for receiving high pressure gaseous refrigerant discharged from the compressor; and an inlet connected to the condenser for receiving the high pressure gaseous refrigerant discharged from the compressor; a valve device that selectively opens and closes the outlet and is movable between a closed position where the outlet is closed and an open position where the outlet is opened; a vent passageway having an open end therein, one of the open ends communicating with the condenser when the valve device is in the closed position, and communicating with the condenser when the valve device is in the open position. a spring device configured to substantially prevent communication with the valve; a spring device configured to bias the valve device toward the valve-closed position; suction means for creating a substantial vacuum in the vent passageway when the device is in the open valve position, the suction means configured to provide a means for displacing the valve device in the closed position while the compressor is in operation; The valve arrangement is moved into the open position against a biasing force exerted by the spring arrangement when the valve arrangement is in the open position to prevent repeated movement to and from the open position. A vent valve and baffle assembly operative to create a substantial vacuum within the vent passageway to maintain the valve in the valve position. 2. A valve shaft having an inlet for receiving a fluid flow, an outlet for supplying a fluid flow, and a ventilation passage extending through the interior and having open ends at both ends, and a closed position in which the outlet is closed. a valve member provided at the outlet so that the outlet can reciprocate between an open position and a spring device for biasing the valve member toward the closed position;
support means for supporting the valve member when the valve member is in the valve open position, the support means including a bearing member for slidably receiving the valve stem, and an opening of the ventilation passage of the valve stem. one of the ends is closed by the bearing member when the valve member is in the open position and open by the bearing member when the valve member is in the closed position, and the support means further includes suction means. It contains
The suction means is connected to the other open end of the ventilation passage of the valve shaft, and when the valve member is in the open position, draws fluid from within the ventilation passage to create a vacuum state within the ventilation passage. A fluid exhaust valve assembly configured to support the valve member against a biasing force applied by the spring device.